Derivatives of 4(3H)-quinazolone, process of preparation, and pharmaceutical compositions thereof

ABSTRACT

A derivative of 4(3H)-quinazolone, its method of preparation, and pharmaceutical compositions are described. In particular, 2methyl-3-(o-cyanophenyl)-4(3H)-quinazolone and its acid addition salts are described. This compound may be prepared by the reaction of N-acetylanthranilic acid with anthranilonitrile in the presence of a dehydrating agent. The quinazolone and it salts possess pharmacological activity.

United States Patent 1191 Taylor et al.

1451 Dec. 23, 1975 [54] DERIVATIVES OF 4(3H)-QUINAZOLONE, PROCESS OF PREPARATION, AND

PHARMACEUTICAL COMPOSITIONS THEREOF [75] Inventors: John Bodenham Taylor, Down 'Ampley; Derek Ralph Harrison,

Swindon, both of England [73] Assignee: Roussel Uclaf, Paris, France [22] Filed: Oct. 21, 1974 [211 App]. No.: 516,779

[30] Foreign Application Priority Data Oct. 23, 1973 United Kingdom 49338/73 52 us. c1 260/2564 .Q; 424/251 511 1111. cm c071) 239/90 58 1 Field of Search 260/2564 Q [56] References Cited UNITED STATES PATENTS 3,086,910 4/1963 Shetty et a1 260/256.4 Q

3,448,109 6/1969 Heusher et al 260/256.4 Q 3,819,627 6/1974 Ott 260/256.4 Q

FOREIGN PATENTS OR APPLICATIONS 31,039 11/1964 Germany OTHER PUBLICATIONS Daleva et al., Tr. Nauchnoizsled Khim-Farm. Inst (1972) 7, 241-252 (Bulg.) from abst. 7922721412 Primary Examiner-Donald G. Daus Assistant Examiner-David E. Wheeler Attorney, Agent, or Firm-Bacon & Thomas 3 Claims, No Drawings tion is 2-methyl-3-(o-cyanophenyl)-4(31-1)-quinazolone of the formula 1:

and its acid addition salts.

The acid addition salts may be derived from inorganic or organic acids, in particular from mineral acids such as hydrochloric, hydrobromic, nitric, sulphuric or phosphoric acid. The organic acids include organic carboxylic acids such as acetic, formic, benzoic, maleic, fumaric, succinic, tartaric, citric, oxalic, benzilic, glyoxylic, and aspartic acid; and organic sulphonic acids such as alkanesulphonic and arylsulphonic acids, e.g. methane sulphonic acid and p-toluenesulphonic acid. 2-Methyl-3-(o-cyanopheny1)-4(3H)-quinazo1one hydrochloride is the particularly preferred salt.

The quinazolone and its pharmaceutically acceptable acid addition salts have been found to possess pharmacological activity. Such pharmacological activity includes, in particular, hypnotic sedative and anticonvulsant activity, and a further feature of the present invention are pharmaceutical compositions containing 2 methyl-3-(o-cyanophenyl)-4(3H)-quinazolone or an acid addition salt thereof together with a pharmaceutical carrier or excipient. Such compositions may be used in the treatment of insomnia, anxiety, irritability, hyperemotivity and neurotic conditions in man and animals. The dose will vary with the type site of administration, the particular condition being treated, the compound used and the subject. However, a typical range for the daily dose per os may be from 5 to 500 mg.

These compositions may be presented in any convenient form for oral, parenteral or rectal administration, e.g. tablets, coated tablets, capsules, granules, suppositories and injection solutions, prepared by conventional methods and containing conventional carriers and excipients, e.g. talc, gum arabic, lactose, starch, magnesium stearate, cocoa butter, aqueous or nonaqueous vehicles, animal and vegetable oils and fats, paraffin derivatives, glycols, wetting, dispersing and emulsifying agents and preservatives.

2Methyl-3-(o-cyanophenyl)-4(3H)-quinazolone and acid addition salts thereof may be prepared by any conventional method, but a particularly preferred method which is a further feature of the present invention comprises reacting N-acetylanthranilic acid with anthranilonitrile in the presence of a dehydrating agent. The dehydratingagent is preferably a phosphorus halide, advantageously phosphorus trichloride, pentachloride or oxychloride. The reaction is preferably 2 effected in an inert organic solvent, in particular, an aromatic hydrocarbon such as toluene, xylene, or benzene.

The reaction is advantageously effected at the boiling point of the reaction mixture under reflux, and then cooled. The product precipitates from the cooled reaction mixture and may be purified by treatment with alkali, such as sodium bicarbonate solution and then extracted with an organic solvent such as chloroform.

The acid addition salts may be prepared by reacting stoichiometrical proportions of the desired acid and the free base. Salts may also be prepared from existing salts by anion exchange techniques.

The following Examples illustrate the invention.

EXAMPLE 1 2-Methyl-3(o-cyanopheny1)-4( 3H )-quinazolone and its hydrochloride Phosphorus trichloride (16 ml) in toluene ml) was added over 15 minutes to anthranilonitrile (40 g) and N-actylanthranilic acid (60g) in toluene (500 ml) stirred under reflux. The mixture was stirred under reflux for 3 hours, cooled and the precipitate filtered off. The precipitate was neutralised with a saturated sodium bicarbonate solution, extracted with chloroform and the extracts washed with water. Evaporation of the dried extracts gave a pale yellow solid which was crystallised from methanol to give colourless crystals of 2-methyl-3-(o-cyanophenyl)-4(3H)-quinazo1one (36g, 41%), mp. -6, ir: 2235 (C N), 1700 (C=O) cm"; nmr T (CDC1 1.71 (1H, cl, .1 7H2, .S-H), 2. 1-2.8. (7H, m, ArH), 7.78 (3H, s, 2-me).

Anal. Calcd. for C H N O C, 73.55; H, 4.24; N, 16.08; Found: C, 73.52; H, 4.56; N, 15.84%

Addition of hydrogen chloride in ether to a solution of the quinazolone in methylene chloride gave colourless crystals of 2-methyl-3-(o-cyanophenyl)-4(3H)-oxo quinasolinium hydrochloride, m.p. 165-75; ir: 2300 (broad) (NH), 2240 (C E N), 1730 (C=O) cm"; nmr r (d DMSO) 1.7.2.4. (80H, m, ArH), 7.70 (3H, s, 2-Me).

Anal. Calcd. for C H N CIO C, 64.54; H, 4.03; N, 14.11;Cl, 11.96%, Found: C, 64.30; H, 4.32; N, 13.73; C1, 12.24%

EXAMPLE 2 Tablets were prepared which corresponded to the formula:

a) 2-methyl-3-(o-cyanophenyl)-4(3H)- quinazolone hydrochloride 50 mg Excipient q.s. for 1 tablet 200 mg (Excipientzlactose. starch, talcum and magnesium stearate).

b) 2-methyl-3-(o-cyanophenyl-4(3H) quinazolone excipient .s. for 1 tablet (Excipientzas for (a 50 mg 200 mg positive response was recorded if the mouse failed to regain righting reflex during a 30 sec. observation. From the results obtained a dose response line was constructed and the dose producing 50% loss of righting reflex was estimated for each observation time. This ED value (the dose producing loss of righting reflex in 50% of a group of mice) was quoted for the time of peak activity. Results appear in table 1.

2. Rotating Drum Test:

Table l Tests ED (Doses in mg/Kg) 2-methyl-3-(o-cyanoethaqualone (Z-methylphenyl)-4(3H)- 3-(oto yl-4(3H)-quinazoquinazolone, HCl lone) Righting Reflex Test in Mouse Rotating Drum Test in Mouse Anticonvulsant Test Against Electroshock in Mouse Potentiation of Hexobarbitone Sleeping Time in Mouse Acute Toxicity ip. 47 i.p. 81 p.o. l 12 p.o. 160 i.p. 26.5 i.p. 30 p.o. 23.0 p.o. 49 i.p. l0 i.p. 21.5

p.o. 9 p.o. 42

i.p. 9.0 i.p. LD i.p. 570 LB ip 550 Groups of ten mice received p.o. or i.p. the test compound at various dose levels, a control group receiving the vehicle alone by each route. min. after dosing each group of mice was placed on a 30 cm diameter rotating drum revolving at l revolution/minute. The mice were placed on the drum against its direction of movement and the number of mice falling off within a 2 min. test period was noted. From the results obtained a dose response line was constructed and the dose causing 50% of the mice to fall off the drum (ED was estimated. Results appear in table 1.

3. Anticonvulsant Test Against Electroshock:

Groups of ten mice received p.o. or i.p. the test compound at various dose levels, a control group received the vehicle alone. 30 min. after dosing, each group was then shocked via auricular electrodes using the electroshock apparatus (Ugo Basile ECT apparatus for small mammals) using the following parameters:

Pulse width 0.2 ms Frequency 100 Hz Pulse duration 0.2 s

Current 55 mA The number of mice which underwent tonic extension of hind limbs was noted. The dose protecting 50% of the mice (ED was estimated. Results appear in table 1.

4. Potentiation of Hexobarbitone Sleeping Time:

A group of eight control mice received a dose of 65 mg/kg Hexobarbitone Sodium iv and subsequent sleeping times were recorded. A time value equivalent to mean sleeping time plus two standard deviations was established as a cut-off point. Other groups of eight mice received an identical dose of Hexobarbitone Sodium and at half the means control sleeping time were given various doses of the test compound i.p. The number of mice in each group asleep at the cut-off point was recorded. A dose response curve was constructed and the dose at which 50% of the mice remained asleep at this cut-off point (ED was estimated. Results appear in table 1.

These results show that 2-methyl-3-(o-cyanophenyl)- 4(3H)-quinazolone hydrochloride is a very effective oral hypnotic in mouse, with a better therapeutic ratio than Methaqualone.

II. The activity of 2-methyl-3-(o-cyanophenyl)-4(3H)- quinazolone hydrochloride was also investigated in rat by the following tests.

1. Righting Reflex Test:

Groups of ten male Sprague-Dawley rats received the test compound i.p. or p.o. at various doses. The animals dosed i.p. were assessed for loss of righting reflex immediately after dosing and those dosed p.o. were assessed at A, /2, l, 2, 4 and 6 hours after dosing. ED values were estimated as for the Righting Reflex Test in the mouse and are shown in table 2.

2. Acute Toxicity Test:

Groups of ten rats were dosed p.o. or i.p. with various doses of the test compound and after 24 hours were assessed for mortality. Results appear in table 2.

The activity of Methaqualone was investigated in the same conditions. Results appear in table 2 below.

These results show that 2-methyl-3(ocyanophenyl)- 4(3H)-quinazolone hydrochloride is less toxic, and much more effective than Methaqualone in the rat.

What is claimed is:

l. A compound selected from the group consisting of Z-methyl-3 -(o-cyanophenyl)-4(3H)-quinazolone of the formulalz' 6 and its pharmaceutically acceptable acid addition salts. 2. A compound of claim 1 wherein the salt is the hydrochloride. 3. A compound of claim 1, which is 2-methyl-3-(0- cyanophenyl )-4( 3 H )-quinazoione. 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 2METHYL-3-(O-CYANOPHENYL)-4(3H)-QUINAZOLONE OF THE FORMULA 1:,
 2. A compound of claim 1 wherein the salt is the hydrochloride.
 3. A compound of claim 1, which is 2-methyl-3-(o-cyanophenyl)-4(3H)-quinazolone. 